These bearings appear to be of high quality and are machined to close tolerances. No slop or play after install. The only complaint I have is that the ring that is supposed to hold the bearing in the bushing or tube without slipping in should be harder to loosen. I use them on Predator 212cc karts. I had to replace the bearing because a circlip broke off somewhere and the bearing failed. Luckily I bought a pack of 6 so I have spares.